1. Field of the Invention
The invention concerns a cap for accumulator elements with a device for the automatic refill of the water, where the cap is inserted into said elements, it is connected by means of pipe joints to a circuit for water refilling and it presents a float opening and closing a valve in said device.
2. Description of Background Art
It is known that accumulator batteries, particularly vehicle batteries, during their operation lose part of the water being diluted in the sulfuric acid solution. This fact leads to the lowering of the electrolyte level in the elements of the accumulator and to a variation in the density of the electrolyte, so that it becomes necessary to add water in order to prevent the lowering of the electrolyte level from causing the deterioration of the accumulator together with a lowering of the energy performance of the same.
For this reason, systems for the automatic refilling of distilled water into the accumulator battery elements are becoming more and more popular. They foresee a feeding tank connected by means of pipes to the refilling caps which are interconnected with each other, each of them being provided with openings for the water inlet and outlet and with pipe joints which connect them together.
When, by means of the refilling, the necessary level of electrolyte has been reached in each element, the float shut the valve being present in the cap.
Several caps for battery elements complete with float are known.
A known type of cap foresees that the shaft supporting the valve is vertical and in line with the stick supporting the float.
A disadvantage presented by said solution consists in the fact that the shutting force of the valve is equal to the hydraulic push which is impressed on the float by the electrolyte, namely a rather weak force which can not prevent the valve from opening again, particularly while it is in operation.
In another device, described in patent DE No. 3127619, the float is connected to a re-inforcing lever, the end of which is also connected to a shaft presenting in its center a cogged segment in a cavity of the stem of the valve body.
Thus it is obtained that the transmission ratio from the float guiding shaft to re-inforcing lever corresponds to 1:16. Even though this shutting device grants the shutting of the valve thanks to the multiplication of the hydraulic push of the float conveying a sufficient force, this device appears rather complicated because of the presence of the cogged shaft which intervenes between an arm of the lever and the valve stick.
For this reason this device is rather costly.
It is necessary to point out also, that a characteristic being common to all the known devices with a float is that the float consists of a practically cylindrical, hollow container, which is sealed by soldering or gluing, so that it remains light in order to exploit as much as possible the hydraulic pushing force, when it is immerged.
If and when the seal of the float breaks and, therefore, the electrolyte enters inside the float, the penetration of the liquid obliterates the hydraulic push on the float, thereby causing the inconvenience that the valve stays open even when the level of the liquid is higher than desired.